1. Technical Field
The present invention relates to an image capturing optical lens system. More particularly, the present invention relates to a compact image capturing optical lens system applicable to electronic products and three-dimensional (3D) image applications thereof.
2. Description of Related Art
In recent years, with the popularity of mobile products with camera functionalities, the demand of miniaturized optical lens systems is increasing. The sensor of a conventional photographing camera is typically a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor. As the advanced semiconductor manufacturing technologies have allowed the pixel size of sensors to be reduced and compact optical lens systems have gradually evolved toward the field of higher megapixels, there is an increasing demand for compact optical lens systems featuring better image quality.
A conventional compact optical lens system employed in a portable electronic product mainly adopts a structure of four-element lens system such as the one disclosed in U.S. Pat. No. 7,869,142. Due to the popularity of mobile products with high-end specifications, such as smart phones and PDAs (Personal Digital Assistants), the requirements for high resolution and image quality of modern compact optical lens systems has been increasing significantly. However, the conventional four-element lens structure cannot satisfy these requirements of the compact optical lens system.
Although other conventional optical lens systems with five-element lens structure such as the ones disclosed in U.S. Pat. No. 8,000,030 enhance the image quality, the distribution of the refractive power of the fourth lens element and the fifth lens element cannot effectively reduce the back focal length of the optical lens system, so that it is hard to integrate the optical lens system to compact electronic products.